Characterization of a hormone response element in the mouse N-acetyltransferase 2 (Nat2*) promoter.
Characterization of a hormone response element in the mouse N-acetyltransferase 2 (Nat2*) promoter.
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发表时间：
1998
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通讯作者：
L. Estrada-Rodgers;G. Levy;W. Weber
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作者：
L. Estrada-Rodgers;G. Levy;W. Weber
人类芳香胺N-乙酰转移酶基因的多个变异等位基因，NAT 1 * 和NAT 2 *，改变个体通过N-乙酰化代谢芳香胺的能力。虽然生物化学和遗传学的研究已经提高了我们的乙酰化多态性在人类和其他哺乳动物的分子基础的理解，NAT* 基因的表达调控是不理解的。在本研究中，小鼠Nat 2 * 的5 '-非翻译区的一个片段进行了测序和表征。引物延伸分析和RNA酶保护试验暴露了位于翻译起始位点上游112至151个碱基的多个转录起始位点。计算机序列分析揭示了位于翻译起始位点上游530个碱基的区域内的启动子样区域，其由TATA盒、上游启动子元件如CAAT盒和Sp1结合位点、调节元件如回文激素反应元件（HRE）和增强子区域如AP-1转录因子结合位点组成。小鼠Nat 2 *-回文HRE的CAT报告基因构建体的瞬时表达证明了HSV-胸苷激酶1（tk 1）启动子的正调控，并诱导氯霉素乙酰转移酶（CAT）的表达。这种诱导是通过添加激素如5 α-二氢睾酮（DHT）或地塞米松启动的，并且完全依赖于雄激素或糖皮质激素受体的存在。结合最近关于睾酮对小鼠肾脏发育过程中Nat 2 * 表达的影响的发现，本文报道的研究结果表明，在Nat 2 * 启动子区域发现的HRE是介导小鼠肾脏Nat 2 * 雄激素调节的潜在候选者。
Multiple variant alleles of the human arylamine N-acetyltransferase genes, NAT1* and NAT2*, alter the capacity of individuals to metabolize arylamines by N-acetylation. Although biochemical and genetic studies have improved our understanding of the molecular basis of the acetylation polymorphism in humans and other mammals, regulation of NAT* gene expression is not understood. In the present study, a segment of the 5'-untranslated region of mouse Nat2* was sequenced and characterized. Primer extension analysis and RNase protection assays exposed multiple transcription initiation sites located 112 to 151 bases upstream of the translational start site. Computer sequence analysis revealed a promoter-like region located within the region 530 bases upstream of the translational start site consisting of TATA boxes, upstream promoter elements such as a CAAT box and Sp1 binding site, regulatory elements such as a palindromic hormone response element (HRE), and enhancer regions such as an AP-1 transcription factor binding site. Transient expression of CAT reporter constructs of the mouse Nat2*-palindromic HRE demonstrated positive regulation of the HSV-thymidine kinase 1 (tk1) promoter and induced the expression of chloramphenicol acetyltransferase (CAT). This induction was initiated by the addition of hormones such as 5alpha-dihydrotestosterone (DHT) or dexamethasone and was entirely dependent on the presence of androgen or glucocorticoid receptors, respectively. Together with recent discoveries regarding the effects of testosterone on the expression of Nat2* in mouse kidney during development, the findings reported in this article suggest that the HRE found in the promoter region of Nat2* is a potential candidate for the mediation of androgenic regulation of Nat2* in mouse kidney.